Sorry for this - for some reason it was a lot easier before and my domain was working fine before - I am registered with 123-reg and the domain is mine - do I need to do domain mapping here on WordPress to cultureandlife.co.uk or the other way around - can I be a real pain and ask for a step by step guide.

Your domain is already mapped here with WordPress.com, as it needs to be. Everything here is setup correctly.

There are two things that are incorrect about the current situation:

The domain has expired with 123-reg.

Because the domain has expired, the nameservers (which point the domain at your site with WordPress.com) are not the correct ones.

To fix this, you will need to contact 123-reg and renew your domain. Once you have done so, you will need to point your nameservers to WordPress.com's nameservers, which I included in my original post. The folks at 123-reg should be able to help you out with how to do that!